temperature gauge

Hi all, time for my next weird issue. Again, I hope this is only a weird issue to me. The Vulcan is running great, I think I chased down it's electrical gremlins related to lighting, and now I'm dealing with some cooling system oddities. I think I have two issues. One related to temperature...

So I changed the coolant. I never could get anything to squirt out the bleeder valve under the tank though I put 3/4 a jug of fluid in it. I did rock the bike back and forth on the center stand so any bubble would get released. I rode to work yesterday, it was 39 degrees in the morning and...